Previous studies on body ownership illusions have shown that under certain multimodal conditions, healthy people can experience artificial body-parts as if they were part of their own body, with direct physiological consequences for the real limb that gets ‘substituted’. In this study we wanted to assess (a) whether healthy people can experience ‘missing’ a body-part through illusory ownership of an amputated virtual body, and (b) whether this would cause corticospinal excitability changes in muscles associated with the ‘missing’ body-part. (...) Forty right-handed participants saw a virtual body from a first person perspective but for half of them the virtual body was missing a part of its right arm. Single pulse transcranial magnetic stimulation was applied before and after the experiment to left and right motor cortices. Motor evoked potentials (MEPs) were recorded from the first dorsal interosseous (FDI) and the extensor digitorum communis (EDC) of each hand. We found that the stronger the illusion of amputation and arm ownership, the more the reduction of MEP amplitudes of the EDC muscle for the contralateral sensorimotor cortex. In contrast, no association was found for the EDC amplitudes in the ipsilateral cortex and for the FDI amplitudes in both contralateral and ipsilateral cortices. Our study provides evidence that a short-term illusory perception of missing a body-part can trigger inhibitory effects on corticospinal pathways and importantly in the absence of any limb deafferentation or disuse. (shrink)

The action observation networks (AON) (or the mirror neuron system) are the neural underpinnings of visuomotor integration and play an important role in motor control. Besides, one of the main functions of the human mirror neuron system is recognition of observed actions and the prediction of its outcome through the comparison with the internal mental motor representation. Previous studies focused on the human mirror neurons (MNs) activation during object-oriented movements observation, therefore intransitive movements observation effects on MNs activity remains relatively (...) little-studied. Moreover, the dependence of MNs activation on the biomechanical characteristics of observed movement and their biological plausibility remained highly underexplored. In this study we proposed that naturalness of observed intransitive movement can modulate the MNs activity. Event-related desynchronization (ERD) of sensorimotor electroencephalography (EEG) rhythms, N400 event-related potentials (ERPs) component and corticospinal excitability were investigated in twenty healthy volunteers during observation of simple non-transitive finger flexion that might be either biomechanically natural or unnatural when finger wriggled out toward the dorsal side of palm. We showed that both natural and unnatural movements caused mu/beta-desynchronization, which gradually increased during the flexion phase and returned to baseline while observation of extension. Desynchronization of the mu-rhythm was significantly higher during observation of the natural movements. At the same time, beta-rhythm was not found to be sensitive to the action naturalness. Also, observation of unnatural movements caused an increased amplitude of the N400 component registered in the centro-parietal regions. We suggest that the sensitivity of N400 to intransitive action observation with no explicit semantic context might imply the broader role of N400 sources within AON. Surprisingly, no changes in corticospinal excitability were found. This lack of excitability modulation by action observation could be related with dependence of the M1 activity on the observed movement phase. (shrink)

Transcranial direct current stimulation over the contralateral primary motor cortex of the target muscle has been described to enhance corticospinal excitability, as measured with transcranial magnetic stimulation. Recently, tDCS targeting the brain regions functionally connected to the contralateral primary motor cortex was reported to enhance corticospinal excitability more than conventional tDCS. We compared the effects of motor network tDCS, 2 mA conventional tDCS, and sham tDCS on corticospinal excitability in 21 healthy participants in a (...) randomized, single-blind within-subject study design. We applied tDCS for 12 min and measured corticospinal excitability with TMS before tDCS and at 0, 15, 30, 45, and 60 min after tDCS. Statistical analysis showed that neither motor network tDCS nor conventional tDCS significantly increased corticospinal excitability relative to sham stimulation. Furthermore, the results did not provide evidence for superiority of motor network tDCS over conventional tDCS. Motor network tDCS seems equally susceptible to the sources of intersubject and intrasubject variability previously observed in response to conventional tDCS. (shrink)

A decrease in cortical excitability tends to be easily followed by an increase induced by external stimuli via a mechanism aimed at restoring it; this phenomenon is called “homeostatic plasticity.” In recent years, although intervention methods aimed at promoting motor learning using this phenomenon have been studied, an optimal intervention method has not been established. In the present study, we examined whether subsequent motor learning can be promoted further by a repetitive passive movement, which reduces the excitability of (...) the primary motor cortex before motor learning tasks. We also examined the relationship between motor learning and the brain-derived neurotrophic factor. Forty healthy subjects participated. Subjects were divided into two groups of 20 individuals each. The first group was assigned to perform the motor learning task after an intervention consisting in the passive adduction–abduction movement of the right index finger at 5 Hz for 10 min, while the second group was assigned to perform the task without the passive movement. The motor learning task consisted in the visual tracking of the right index finger. The results showed that the corticospinal excitability was transiently reduced after the passive movement in the RPM condition, whereas it was increased to the level detected in the control condition after the motor learning task. Furthermore, the motor learning ability was decreased immediately after the passive movement; however, the motor performance finally improved to the level observed in the control condition. In individuals carrying the Val/Val genotype, higher motor learning was also found to be related to the more remarkable changes in corticospinal excitability caused by the RPM condition. This study revealed that the implementation of a passive movement before a motor learning tasks did not affect M1 excitatory changes and motor learning efficiency; in contrast, in subjects carrying the Val/Val polymorphism, the more significant excitatory changes in the M1 induced by the passive movement and motor learning task led to the improvement of motor learning efficiency. Our results also suggest that homeostatic plasticity occurring in the M1 is involved in this improvement. (shrink)

There is a growing interest in non-invasive stimulation interventions as treatment strategies to improve functional outcomes and recovery after spinal cord injury. Repetitive transcranial magnetic stimulation is a neuromodulatory intervention which has the potential to reinforce the residual spinal and supraspinal pathways and induce plasticity. Recent reviews have highlighted the therapeutic potential and the beneficial effects of rTMS on motor function, spasticity, and corticospinal excitability modulation in SCI individuals. For this scoping review, we focus on the stimulation parameters (...) used in 20 rTMS protocols. We extracted the rTMS parameters from 16 published rTMS studies involving SCI individuals and were able to infer preliminary associations between specific parameters and the effects observed. Future investigations will need to consider timing, intervention duration and dosage that may depend on the stage, the level, and the severity of the injury. There is a need for more real vs. sham rTMS studies, reporting similar designs with sufficient information for replication, to achieve a significant level of evidence regarding the use of rTMS in SCI. (shrink)

BackgroundTranscranial direct current stimulation targeting the primary motor hand area may induce lasting shifts in corticospinal excitability, but after-effects show substantial inter-individual variability. Functional magnetic resonance imaging can probe after-effects of TDCS on regional neural activity on a whole-brain level.ObjectiveUsing a double-blinded cross-over design, we investigated whether the individual change in corticospinal excitability after TDCS of M1-HAND is associated with changes in task-related regional activity in cortical motor areas.MethodsSeventeen healthy volunteers received 20 min of real or (...) sham TDCS on separate days in randomized order. Real and sham TDCS used the classic bipolar set-up with the anode placed over right M1-HAND. Before and after each TDCS session, we recorded motor evoked potentials from the relaxed left first dorsal interosseus muscle after single-pulse transcranial magnetic stimulation of left M1-HAND and performed whole-brain fMRI at 3 Tesla while participants completed a visuomotor tracking task with their left hand. We also assessed the difference in MEP latency when applying anterior-posterior and latero-medial TMS pulses to the precentral hand knob.ResultsReal TDCS had no consistent aftereffects on mean MEP amplitude, task-related activity or motor performance. Individual changes in MEP amplitude, measured directly after real TDCS showed a positive linear relationship with individual changes in task-related activity in the supplementary motor area and AP-LM MEP latency.ConclusionFunctional aftereffects of classical bipolar anodal TDCS of M1-HAND on the motor system vary substantially across individuals. Physiological features upstream from the primary motor cortex may determine how anodal TDCS changes corticospinal excitability. (shrink)

Functional electrical stimulation (FES), a method for inducing muscle contraction, has been successfully used in gait rehabilitation for patients with deficits after neurological disorders and several clinical studies have found that it can improve gait function after stroke and spinal cord injury. However, FES gait training is not suitable for patients with walking difficulty, such as those with severe motor paralysis of the lower limbs. We have previously shown that action observation combined with motor imagery (AO + MI) of walking (...) induces walking-related cortical activity. Therefore, we combined FES, which alternately generates dorsiflexion and plantar flexion, with AO + MI as an alternative to gait training. The present study investigates the transient effects of 20-min of FES simultaneously with and without AO + MI of walking on corticospinal and spinal reflex excitability in able-bodied participants. We measured motor evoked potentials and Hoffmann-reflexes to assess corticospinal and spinal reflex excitability at rest before and after the 20-min FES with and without the AO + MI. Our results show that FES without AO + MI did not change excitability (p > 0.05), while FES with AO + MI facilitated corticospinal excitability (p < 0.05). This facilitation likely occurred due to the synchronization of sensory inputs from FES and cortical activity during AO + MI. Facilitation was observed only in the dorsiflexor but not the plantar flexor muscle (p < 0.05), suggesting muscle specificity of the facilitation. These results demonstrate the effectiveness of combining FES with AO + MI and pave the way for novel neurorehabilitation strategies for patients with neurological gait deficits. (shrink)

IntroductionPrevious transcranial magnetic stimulation studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements.MethodTen healthy right-handed subjects performed four finger tapping tasks with the index finger: simple tapping task, Real-word task, Pseudoword task, and Visually guided tapping task. In the Tap task, the (...) subject performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word. Because the action had a specific purpose, this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition in the resting first dorsal interosseous muscle.ResultsWe found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions.DiscussionWe found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis. (shrink)

The use of upper limb vibration during exercise and rehabilitation continues to gain popularity as a modality to improve function and performance. Currently, a lack of knowledge of the pathways being altered during ULV limits its effective implementation. Therefore, the aim of this study was to investigate whether indirect ULV modulates transmission along spinal and corticospinal pathways that control the human forearm. All measures were assessed under CONTROL and ULV conditions while participants maintained a small contraction of the right (...) flexor carpi radialis muscle. To assess spinal pathways, Hoffmann reflexes elicited by stimulation of the median nerve were recorded from FCR with motor response amplitudes matched between conditions. An H-reflex conditioning paradigm was also used to assess changes in presynaptic inhibition by stimulating the superficial radial nerve 37 ms prior to median nerve stimulation. Cutaneous reflexes in FCR elicited by stimulation of the SR nerve at the wrist were also recorded. To assess corticospinal pathways, motor evoked potentials elicited by transcranial magnetic stimulation of the contralateral motor cortex were recorded from the right FCR and biceps brachii. ULV significantly reduced H-reflex amplitude by 15.7% for both conditioned and unconditioned reflexes. Therefore, ULV inhibits cutaneous and H-reflex transmission without influencing corticospinal excitability of the forearm flexors suggesting increased presynaptic inhibition of afferent transmission as a likely mechanism. A general increase in inhibition of spinal pathways with ULV may have important implications for improving rehabilitation for individuals with spasticity. (shrink)

Transcranial magnetic stimulation studies have demonstrated increased cortical facilitation and reduced inhibition following aerobic exercise, even when examining motor regions separate to the exercised muscle group. These changes in brain physiology following exercise may create favorable conditions for adaptive plasticity and motor learning. One candidate mechanism behind these benefits is the increase in brain-derived neurotropic factor observed following exercise, which can be quantified from a venous blood draw. The aim of this study was to investigate changes in motor cortex (...) class='Hi'>excitability and inhibition of the upper limb, and circulating BDNF, following high-intensity interval training on a stationary bicycle. Nineteen sedentary adults participated in a randomized crossover design study involving a single bout of high-intensity interval cycling for 20 min or seated rest. Venous blood samples were collected, and transcranial magnetic stimulation was used to stimulate the extensor carpi radialis, where motor evoked potentials were recorded pre- and post-condition. Following exercise, there was a significant increase in corticospinal excitability measured at 120% of resting motor threshold and a reduction in short-interval cortical inhibition. There was a non-significant 23.6% increase in BDNF levels. Collectively, these results reflect a net reduction in gamma aminobutyric acid ergic synaptic transmission and increased glutamatergic facilitation, resulting in increased corticospinal excitability. This study supports the notion that acute high-intensity exercise provides a potent stimulus for inducing cortical neuroplasticity, which may support enhanced motor learning. (shrink)

Paired associative stimulation at the spinal cord has been shown to increase muscle force and dexterity by strengthening the corticomuscular connection, through spike timing dependent plasticity. Typically, transcranial magnetic stimulation and transcutaneous peripheral nerve electrical stimulation are often used in spinal PAS. PNS targets superficial nerve branches, by which the number of applicable muscles is limited. Alternatively, a muscle can be activated by positioning the stimulation electrode on the “motor point”, which is the most sensitive location of a muscle to (...) electrical stimulation. Although this can increase the number of applicable muscles for spinal PAS, nobody has tested whether MPS can be used for the spinal PAS to date. Here we investigated the feasibility of using MPS instead of PNS for spinal PAS. Ten healthy male individuals received spinal PAS on two separate days with different stimulation timings expected to induce facilitation of corticospinal excitability or no effect on the soleus. The motor evoked potentials response curve in the soleus was measured prior to the spinal PAS, immediately after and at 10, 20, 30 min post-intervention as a measure of corticospinal excitability. The post-intervention MEP response curve areas were larger in the REAL condition than the CONTROL conditions. Further, the post-intervention MEP response curve areas were significantly larger than pre-intervention in the REAL condition but not in the CONTROL condition. We conclude that MPS can facilitate corticospinal excitability through spinal PAS. (shrink)

BackgroundNeuroimaging studies have shown a complex pattern of brain activation during perception of a pleasant odor and during its olfactory imagery. To date, little is known regarding changes in motor cortex excitability during these tasks. Bergamot essential oil is extensively used in perfumes and cosmetics for its pleasantness. Therefore, to further our understanding of the human sense of smell, this study aimed to investigate the effect of perception and imagery of a pleasant odor on motor cortex using Transcranial magnetic (...) stimulation.Materials and MethodsWe examined the primary motor cortex excitability during perception of a pleasant odor or perception of odorless saline. Furthermore, we tested the effect of olfactory imagery of BEO on corticospinal excitability. The increase in motor evoked potential amplitude was correlated with personality dimensions scores, pleasantness, vividness, and general imagery ability.ResultsThe results indicate that the corticospinal excitability changed after both perception and imagery of a pleasant odor. The correlation analysis shows an association with neuroticism personality trait and with general olfactory imagery ability.ConclusionBoth perception of a pleasant odor and its olfactory imagery modulate motor cortex excitability. The enhanced brain activation is affected by specific individual characteristics. Overall, our findings provide physiological evidence for a complex interaction between the olfactory and motor systems. (shrink)

Short-term motor practice leads to plasticity in the primary motor cortex. The purpose of this study is to investigate the factors that determine the increase in corticospinal tract excitability after motor practice, with special focus on two factors; “the level of muscle activity” and “the presence/absence of a goal of keeping the activity level constant.” Fifteen healthy subjects performed four types of rapid thumb adduction in separate sessions. In the “comfortable task” and “forceful task”, the subjects adducted their (...) thumb using comfortable and strong forces. In the “comfortable with a goal task” and “forceful with a goal task”, subjects controlled the muscle activity at the same level as in the C and F, respectively, by adjusting the peak electromyographic amplitude within the target ranges. Paired associative stimulation, which combines peripheral nerve stimulation and transcranial magnetic stimulation, with an inter-stimulus interval of 25 ms was also done. Before and after the motor tasks and PAS25, TMS was applied to the M1. None of the four tasks showed any temporary changes in behavior, meaning no learning occurred. Motor-evoked potential amplitude increased only after the FG and it exhibited a positive correlation with the MEP increase after PAS25, suggesting that FG and PAS25 share at least similar plasticity mechanisms in the M1. Resting motor threshold decreased only after FG, suggesting that FG would also be associated with the membrane depolarization of M1 neurons. These results suggest task-dependent plasticity from the synergistic effect of forceful muscle activity and of setting a goal of keeping the activity level constant. (shrink)

With the same intellectual courage with which she addressed issues of gender, Judith Butler turns her attention to speech and conduct in contemporary political life, looking at several efforts to target speech as conduct that has become subject to political debate and regulation. Reviewing hate speech regulations, anti-pornography arguments, and recent controversies about gay self-declaration in the military, Judith Butler asks whether and how language acts in each of these cultural sites.

With the same intellectual courage with which she addressed issues of gender, Judith Butler turns her attention to speech and conduct in contemporary political life, looking at several efforts to target speech as conduct that has become subject to political debate and regulation. Reviewing hate speech regulations, anti-pornography arguments, and recent controversies about gay self-declaration in the military, Judith Butler asks whether and how language acts in each of these cultural sites.

Here we elucidate a paradox: how a single chemoattractant‐receptor system in two individuals is used for communication despite the seeming inevitability of self‐excitation. In the filamentous fungus Neurospora crassa, genetically identical cells that produce the same chemoattractant fuse via the homing of individual cell protrusions toward each other. This is achieved via a recently described “ping‐pong” pulsatile communication. Using a generic activator‐inhibitor model of excitable behavior, we demonstrate that the pulse exchange can be fully understood in terms of two excitable (...) systems locked into a stable oscillatory pattern of mutual excitation. The most puzzling properties of this communication are the sudden onset of oscillations with final amplitude, and the absence of seemingly inevitable self‐excitation. We show that these properties result directly from both the excitability threshold and refractory period characteristic of excitable systems. Our model suggests possible molecular mechanisms for the ping‐pong communication. (shrink)

To commemorate 40 years since the founding of the Journal of Business Ethics, the editors-in-chief of the journal have invited the editors to provide commentaries on the future of business ethics. This essay comprises a selection of commentaries aimed at creating dialog around the theme Bringing Excitement to Empirical Business Ethics Research (inspired by the title of the commentary by Babalola and van Gils). These editors, considering the diversity of empirical approaches in business ethics, envisage a future in which quantitative (...) business ethics research is more bold and innovative, as well as reflexive about its techniques, and dialog between quantitative and qualitative research nourishes the enrichment of both. In their commentary, Babalola and van Gils argue that leadership research has stagnated with the use of too narrow a range of perspectives and methods and too many overlapping concepts. They propose that novel insights could be achieved by investigating the lived experience of leadership (through interviews, document analysis, archival data); by focusing on topics of concern to society; by employing different personal, philosophical, or cultural perspectives; and by turning the lens on the heroic leader (through “dark-side” and follower studies). Taking a provocative stance, Bal and Garcia-Lorenzo argue that we need radical voices in current times to enable a better understanding of the psychology underlying ethical transformations. Psychology can support business ethics by not shying away from grander ideas, going beyond the margins of “unethical behaviors harming the organization” and expanding the range of lenses used to studying behavior in context. In the arena of finance and business ethics, Guedhami, Liang, and Shailer emphasize novel data sets and innovative methods. Significantly, they stress that an understanding the intersection of finance and ethics is central to business ethics; financial equality and inclusion are persistent socio-economic and political concerns that are not always framed as ethics issues, yet relevant business policies and practices manifest ethical values. Finally, Charles Cho offers his opinion on the blurry line between the “ethical” versus “social” or “critical” aspects of accounting papers. The Journal of Business Ethics provides fertile ground for innovative, even radical, approaches to quantitative methods (see Zyphur and Pierides in J Bus Ethics 143(1):1–16, https://doi.org/10.1007/s10551-017-3549-8, 2017), as part of a broad goal of ethically reflecting on empirical research. (shrink)

We report that upon excitation by a single pulse, a classical harmonic oscillator immersed in the classical electromagnetic zero-point radiation exhibits a discrete harmonic spectrum in agreement with that of its quantum counterpart. This result is interesting in view of the fact that the vacuum field is needed in the classical calculation to obtain the agreement.

One of the most oft-cited parts of Francis Hutcheson’s Illustrations upon the Moral Sense (1728) is his discussion of “exciting reasons.” In this paper I address the question: What is the function of that discussion? In particular, what is its relation to Hutcheson’s attempt to show that the rationalists’ normative thesis ultimately implies, contrary to their moral epistemology, that moral ideas spring from a sense? Despite first appearances, Hutcheson’s discussion of exciting reasons is not part of that attempt. Mainly, it (...) is part of Hutcheson’s comeback to Gilbert Burnet’s objections to Hutcheson’s Inquiry into the Original of Our Ideas of Beauty and Virtue (1725). (shrink)

“Excited Delirium Syndrome” (ExDS) is a controversial diagnosis. The supposed syndrome is sometimes considered to be a potential cause of death. However, it has been argued that its sole purpose is to cover up excessive police violence because it is mainly used to explain deaths of individuals in custody. In this paper, we examine the epistemic conditions giving rise to the controversial diagnosis by discussing the relation between causal hypotheses, evidence, and data in forensic medicine. We argue that the practitioners’ (...) social context affects causal inquiry through background assumptions that enter inquiry at multiple stages. This analysis serves to better understand the wide usage of the controversial diagnosis of ExDS. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumFalsifiability, Causality, and the Importance of AdvocacyArjun Byju, MD (bio) and Phoebe Friesen, PhD (bio)We want to begin by thanking both Kathryn Petrozzo and Paul B. Lieberman for taking the time to read and respond to our article, “Making Up Monsters, Redirecting Blame: An Examination of Excited Delirium,” so thoughtfully. They each offered us an opportunity to consider dimensions of excited delirium that we had not encountered as (...) of yet and encouraged us to think more carefully about them. In our response, we consider each of their commentaries in turn, given that, as a philosopher and a psychiatrist, they each speak to different aspects of our argument.First, we turn to Kathryn Petrozzo’s commentary “Excited Delirium: The Self-Fulfilling Prophecy of Police Brutality.” We are grateful for her generous comments and careful engagement with our arguments. While much of the commentary is supportive of our piece, Petrozzo makes three critical and insightful points that we hope to respond to here.The first point Petrozzo makes is that our assertion that excited delirium is non-falsifiable is not supported. She suggests that those “seeking to exonerate the police/first responders responsible for these deaths, are not accepting this evidence leading them to reject the excited delirium diagnosis, but rather, are crafting an incorrect causal narrative. This is deeply problematic, but it does not necessarily render excited delirium as nonfalsifiable.”Although we are intrigued by this challenge, we would like to hear more about what it would look like to falsify the phenomenon of excited delirium. The way that the causal theories related to it are structured are such that if one causal factor is not present (e.g., drug use), then another causal factor can be located (e.g., mental health), and if that is not found, another may be simply made up (e.g., genetic predisposition), making excited delirium multiply realizable in a seemingly endless fashion. This is precisely what took place in the case of Anthany Dawson, who was initially said to have been experiencing a mental health crisis, but was later said to have died from excited delirium related to a genetic condition never identified before (Hon, 2004; Razack, 2015). [End Page 361]In practice, confirmations of excited delirium are found on the basis of various unrelated factors, such that after a death involving police force, there is almost always the option to reach for excited delirium as an explanation/exoneration. According to proponents, there is no factor that could be present that could rule out the diagnosis of excited delirium as it is currently constructed. Indeed, even in the presence of video evidence showing police officers choking an individual until they stop breathing, these deaths are still attributed to excited delirium. This seems like a clear instance of non-falsifiability.Although Petrozzo might maintain that this is simply “an incorrect causal narrative,” it is a causal narrative that aligns with the current theoretical scaffolding surrounding excited delirium.The second point Petrozzo makes is regarding widespread criticisms of Popper’s demarcation criterion of falsifiability. Indeed, this criterion has been called too inclusive, in that any empirical claim can be called falsifiable in principle—even if it refers to a future apocalypse or a UFO landing. It has also been criticized for being too exclusive, in that it ignores the “remarkable tenacity of scientific theories,” as Lakatos puts it (2009, p. 516). In practice, scientists do not merely abandon a theory if it is not supported by facts; they tend to find other explanations (e.g., the measurement was faulty) rather than accept an instance of falsification.Despite this, we believe it is still worth discussing falsifiability in the context of excited delirium for two reasons. First, while falsifiability may not be successful as a criterion that draws a line between science and pseudoscience, in this case, we argue, it still works well as a signifier of pseudoscience. Recently, many interested in the demarcation question have turned towards pluralism as a way to identify pseudoscientific practices (Pigliucci & Boudry, 2013). And excited delirium offers an excellent example of a phenomenon that bumps up against many of the features that might indicate a pseudoscientific practice... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumThe Self-Fulfilling Prophecy of Police BrutalityKathryn Petrozzo (bio)In their timely and pressing piece, Arjun Byju and Phoebe Friesen explore the contentious diagnosis of excited delirium; a syndrome characterized by erratic, aggressive, and “delusional” behavior (2023). Overwhelmingly, this term is used when individuals come in contact with police and/or first responders. Although much attention has been given to debating whether or not this is a “real” diagnosis, the authors (...) want to shift the focus to examining the work that excited delirium is doing in the world, as well as the underlying beliefs guiding it that are perpetuating substantial harm. Drawing significantly on the work of Ian Hacking (1998, 2006) and Sherene Razack (2015), Byju and Friesen explore what kinds of people are being made up by the label of “excited delirium” and the subsequent dehumanization that perpetuates violence towards those in this grouping.Despite the lack of an agreed upon definition, excited delirium tends to frequently group together young Black men and other marginalized people of color, who have a psychiatric history, and those who have taken or are suspected to have taken drugs (Byju & Friezen, 2023). As this is “observed” when individuals come into contact with law enforcement and/or first responders, those who are presumed to be suffering from excited delirium are typically met with physical restraints (chokeholds, hogties, etc.), forced injections of sedatives, and/or taser guns. The violent reactions are often justified not only by this “diagnosis,” but the employment of racial stereotypes; notably, the notion that Black bodies as being less susceptible to pain. As the authors aptly put it:This kind of symptom language helps make up the novel category of a person who suffers from excited delirium: a crazed and inhumane monster, a golem that must be met with unrelenting and superordinate force, who is fated, regardless of interventions, to die a spontaneous death. This paradox, that those with excited delirium are supposedly both too strong and too weak, is at the core of the illness narrative.(2023)It is evident that this label is reinforcing the combination of two harmful stereotypes: the notion that those suffering from severe mental illness occupy a space that is “less than fully human,” and racist stereotyping of Black bodies “superseding human strength.” This perpetuates total dehumanization of the individual, where it is then justified to invoke brutal tactics, as well as signal [End Page 357] to the greater community this is how individuals with mental illnesses and/or belonging to a particular racial group (chiefly, Black men), should be treated. This is despite the fact that those suffering from mental illnesses are significantly more likely to be victims of violent crimes, Black Americans are 3.2 times more likely to be murdered by police, and convergence of these factors (being Black and living with a mental illness) increases likelihood of such fatal interactions (Schwartz & Jahn 2020; Shadravan, Edwards, & Vinson 2021; Stuart, 2003).Although I am in wholehearted support of their account, I take issue with the authors’ conceptualization of excited delirium as non-falsifiable, as well as the notion that diseases, generally, are falsifiable. In an attempt to further criticize the utilization of excited delirium, Byju and Friesen call upon Karl Popper’s falsifiability criterion as a measure for what constitutes as scientific; arguing that excited delirium is not a legitimate scientific concept as it is impossible to falsify. First, I am not convinced that excited delirium is in principle non-falsifiable; as the way in which it’s conceptualized actually appears to be falsifiable. The authors point out that external factors, such as tasing and violent restraints, are clearly the causal explanation, which should in fact, lead one to reject the hypothesis of an excited delirium diagnosis. However, in practice, those who are seeking to exonerate the police/first responders responsible for these deaths, are not accepting this evidence leading them to reject the excited delirium diagnosis, but rather, are crafting an incorrect causal narrative. This is deeply problematic, but it does not necessarily render excited delirium as non-falsifiable. More broadly, I am concerned with the reliance on the falsifiability criterion, which has been widely criticized in the... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumWhat’s Psychiatry Got to do With It?Paul B. Lieberman, MDIf in life we are surrounded by death, so too in the health of our intellect by madness.—WittgensteinDelirium is a medical syndrome defined as “a relatively acute decline in cognition that fluctuates over hours or days” whose primary manifestation is a deficit of attention. It is common, estimated to occur in 10% to more than 50% of hospitalized patients, (...) with higher prevalence rates among people in nursing homes and at the end of life. It is often fatal, with a mortality rate in the hospital estimated to be 25% to 33%. Caused by a wide variety of conditions and frequently difficult to diagnose, it lacks characteristic postmortem pathology (Josephson & Miller 2018)‘Excited delirium,’ as Byju and Friesen forcefully argue (Byju & Friesen, 2023), is, if nothing else, an excuse. The ‘diagnosis’ has not been empirically validated and remains controversial (American Psychiatric Association, 2020). And while delirium is usually treated by internists and emergency medicine physicians, psychiatrists should also be concerned about the misuse of a putative medical diagnosis and join actively in discussion about it. For one thing, patients mis-diagnosed with this condition, as Byju and Friesen’s examples suggest, may actually have another psychiatric condition and, so, be people for whose safety we should advocate. Moreover, the kinds of police interventions which Byju and Friesen document as involving excited delirium also befall patients with other psychiatric problems in whom the issue of delirium does not arise.There are at least two broad ways in which psychiatrists are qualified and obligated to engage with this issue. As physicians, we should join our medical colleagues in carefully but persistently telling the scientific, medical truth. As psychiatrists, we should bring psychiatric knowledge into the discussion, for example, by explaining what can happen when people who do not, apparently, have a diagnosable mental disorder interact under stress with other people who, apparently, do.Delirium is a clinical diagnosis, made when characteristic signs and symptoms are present which should not be made ‘by exclusion’ when, as may happen, other causes are not found. There is no evidence of delirium in any of the three clinical descriptions Byju and Friesen provide. Perhaps such evidence exists which is not in their brief reports, but these three people appear to have had, either, another psychiatric condition, such as psychosis or drug intoxication, or perhaps no [End Page 353] diagnosis at all. Psychiatrists are particularly wellpositioned to make this point since patients with mental health problems are often misdiagnosed when they seek medical attention and are told, and treated as if, “it’s all (“just”!) psychological.”Excited delirium, if it exists, is fatal in 10% of cases (Gonin, Beysard, Hersin, & Carron, 2018) and, although this is lower than the rate for delirium in general, it is still high. Medical personnel must be available to evaluate and ensure the safety of patients in custody.The potential conflict between protecting the patient and protecting the public should not be overstated. Although physical trauma and excessive administration of medications, including ketamine 500 mg IV (Orhurhu, Vashicht, Claus, & Cohen, 2023) can be lethal, mechanical restraint by itself is not (Chieze et al., 2019; Gleerup et al., 2019): something else is necessary, such as asphyxiation (Evans, Wood, & Lambert, 2003). Nor is restraint necessary in many cases in which ‘de-escalation’ techniques can be equally effective (Garriga et al., 2016; Fernández-Costa, 2020). Perhaps these points are best made by law enforcement leaders—and they have been—but psychiatrists can add that safe management of potential violence can be provided for agitated people with psychiatric conditions.Although it is not clear what kind of strength ‘superhuman’ strength might be (certainly not medical), relative imperviousness to pain is clinically described. Its locus classicus is Beecher’s observation, during World War II, that injured soldiers awaiting return home from the front, required lower than usual doses of analgesics (Beecher, 1946). And it’s a common experience, scientifically confirmed, that physical trauma may not become painful until sometime after the injury (Melzack, Wall, & Ty, 1982). But pain is a warning. Its absence is not a license, but a caution... (shrink)

Radial excitations of hadrons carrying zero instanton number are investigated. The mass relations among relevant non-strange and strange mesons and baryons have been derived consistently with the observed data.